A loudspeaker module is an important acoustic component in a portable electronic device and used to perform conversion between an electrical signal and a sound signal, and serves as an energy conversion component. The current loudspeaker module usually comprises a casing in which a speaker unit is received, and the speaker unit divides an inner cavity of the whole module into two cavities, namely, a front acoustic cavity and a rear acoustic cavity. To reduce F0 (low frequency) of the module and expand the bandwidth, a technician usually additionally arrange a sound-absorbing cotton in the rear acoustic cavity, the sound-absorbing cotton may effectively reduce the F0 of the module, makes an intermediate frequency curve smoother and is an important component in the loudspeaker module. A degree of the function of the sound-absorbing cotton in the rear acoustic cavity is directly related to a fill amount of the sound-absorbing cotton in the rear acoustic cavity. Fill of as much as possible sound-absorbing cotton in the rear acoustic cavity is of a positive significance to improvement of the performance of the loudspeaker module.
The rear acoustic cavity of the loudspeaker module in the current stage is usually irregular. The thickness of the current sound-absorbing cotton is fixed. To fill the sound-absorbing cotton with the fixed thickness into the rear acoustic cavity which rises and falls, only a manner of sticking and putting together a plurality of sound-absorbing cottons can be used to ensure adaptation of the sound-absorbing cottons to the rear acoustic cavity. However, this manner makes it very difficult to control closeness between the sound-absorbing cottons and the casing as well as a compression ratio of the sound-absorbing cottons, and causes undesirable consistency of the module; furthermore, according to the manner, the sound-absorbing cottons can only be stuck together manually, worker's labor intensity is large, operation difficulty is high, labor cost is caused high, and therefore, product costs of the product are caused high and the production efficiency is made low.